Incorporation graphene into sprayed epoxy-polyamide coating on carbon steel: corrosion resistance properties

In this study, the graphene incorporated into epoxy-polyamide coatings were successfully obtained on carbon steel substrates by spraying process. The corrosion resistance properties of the coatings were investigated, including salt spray corrosion, sea water corrosion and electrochemical corrosion resistance. The results show that the addition of graphene could improve the corrosion resistance properties of the epoxy-polyamide coatings. The coatings in the presence of graphene had better salt spray corrosion than that in the absence of graphene. The surface of the epoxy-polyamide coating exhibited lots of pitting corrosion. The coatings with the addition of graphene showed better sea water corrosion than the coating without graphene. After drying, the epoxy-polyamide coating in the absence of graphene was broken and failed. The coating with 1 wt-% graphene exhibited the best anticorrosion capability as evidenced by the highest corrosion potential and the lowest corrosion current density. The graphene incorporated into epoxy-polyamide coatings were shown to effectively protect carbon steel against corrosion because the graphene nanosheets could be acted as the good chloride ions, oxygen and water molecules barrier.